On the Unruh effect in de Sitter space

We give an interpretation of the temperature in de Sitter universe in terms of a dynamical Unruh effect associated with the Hubble sphere. As with the quantum noise perceived by a uniformly accelerated observer in static space-times, observers endowed with a proper motion can in principle detect the effect. In particular, we study a "Kodama observer" as a two-field Unruh detector for which we show the effect is approximately thermal. We also estimate the back-reaction of the emitted radiation and find trajectories associated with the Kodama vector fields are stable.Comment: 8 pages; corrected typos; sections structure revise

"PROXIMITY" AS A DESIGN STRATEGY FOR SUSTAINABLE, COLLABORATIVE AND INCLUSIVE URBAN PUBLIC SPACES

Public spaces at neighbourhood scale represent the main scenario of citizens’ life, nodes that define an archipelago of places with a key role in promoting and fostering the enhancement and maintenance of the built environment through mutual collaboration. This network of open and built spaces traces the reference infrastructure of urban planning and redevelopment models, based on proximity as device for physical and social relationship, central in the post-pandemic city debate. “The city of proximity” is the first focus addressed by the Atelier of Urban Innovation Lab in Bologna: an exhibition and laboratory space for comparison and co-design of public space, housed inside the City Hall of the Italian metropolitan city of Bologna and co-curated by the Department of Architecture, University of Bologna and the city agency Foundation for the Urban Innovation. The Atelier explores urban dynamics and contemporary challenges using analogue and digital tools investigating the potential of the ecosystem defining the realm of the everyday dynamics – for instance, squares, courtyards, markets, libraries, urban gardens, playgrounds, sport equipment, etc. In addition to the physical transformations linked to the concept of proximity, the design process, the actors involved and the results obtained are considered relevant. This paper, framing the topic on transition city issues, addresses the potential, transversal andrecurrent features of neighborhood spaces with the aim of acknowledging replicable strategies and design practices for collaborative cities based on new form of citizen democracy that encourage the reactivation of places, community creation, resilience to climate change and sustainable mobility, as experimented by the lab-like environment of Urban Innovation Lab Bologna

WHAT GOES BETWEEN TEACHING AND LEARNING

O presente artigo tem como propósito um convite para pensar o que se passa entre ensinar e aprender em Deleuze e Guattari. Para tanto, parte da ideia de que não se trata de explicar Deleuze, e nem de tomá-lo como critério, mas de ver o transdiferencialismo deleuzo-guattariano como a mais forte inspiração contemporânea a respeito da problemática das conexões verbais em filosofia. Isso é claro para nós, pois não há linhas de fuga sem fugir pelos verbos.The purpose of this article is an invitation to think about what happens between teaching and learning in Deleuze and Guattari. Therefore, it starts from the idea that it is not about explaining Deleuze, nor taking him as a criterion, but seeing deleuzo-guattarian transdifferentialism as the strongest contemporary inspiration regarding the problematic of verbal connections in philosophy. This is clear to us, as there are no lines of flight without escaping through the verbs

Cellular retinol-binding protein-1 expression in endometrial stromal cells: physiopathological and diagnostic implications

Cellular retinol-binding protein-1 (CRBP-1) contributes to the maintenance of the differentiated state of the endometrium through retinol bioavailability regulation. The aim was to analyse CRBP-1 expression in endometrial stromal cells at eutopic and ectopic sites in different physiopathological conditions

Retinoids and cancer: antitumoral effects of ATRA, 9-cis RA and the new retinoid IIF on the HL-60 leukemic cell line.

Objective: To compare the antitumoral effects of all-trans retinoic acid (ATRA) and 9-cis retinoic acid (9-cis RA) with those of 5-OH,11-O-hydrophenanthrene (IIF), a new derivative of retinoic acid. Materials and Methods: The effect of retinoids was tested on cell line HL-60. Cell differentiation and apoptosis were evaluated by morphological and biochemical analysis as bcl-2 protein and by DNA fragmentation assay. The ability to activate retinoic acid receptors (RAR) and/or retinoid X receptors (RXR) and to modulate gene expression was determined by transactivation assay. Results: With cell line HL-60, the antiproliferative effect of IIF was stronger than that of ATRA and 9-cis RA. Following retinoid treatment, cells appeared to differentiate and apoptotic cells were observed. The appearance of DNA laddering and a decrease in the amount of bcl-2 protein confirmed apoptosis. IIF transcriptionally activated RXR-γ more than RAR-α. Conclusion: The findings indicate that IIF transcriptionally activates RXR-γ preferentially, induces apoptosis and has a more antiproliferative activity than ATRA and 9-cis RA on cell line HL-60

Brain natriuretic peptide: Much more than a biomarker.

Brain natriuretic peptide (BNP) modulates several biological processes by activating the natriuretic peptide receptor A (NPR-A). Atria and ventricles secrete BNP. BNP increases natriuresis, diuresis and vasodilatation, thus resulting in a decreased cardiac workload. BNP and NT-proBNP, which is the biologically inactive N-terminal portion of its pro-hormone, are fast and sensitive biomarkers for diagnosing heart failure. The plasma concentrations of both BNP and NT-proBNP also correlate with left ventricular function in patients with acute exacerbation of COPD, even without history of heart failure. Several studies have been conducted in vitro and in vivo, both in animals and in humans, in order to assess the potential role of the NPR-A activation as a novel therapeutic approach for treating obstructive pulmonary disorders. Unfortunately, these studies have yielded conflicting results. Nevertheless, further recent specific studies, performed in ex vivo models of asthma and COPD, have confirmed the bronchorelaxant effect of BNP and its protective role against bronchial hyperresponsiveness in human airways. These studies have also clarified the intimate mechanism of action of BNP, represented by an autocrine loop elicited by the activation of NPR-A, localized on bronchial epithelium, and the relaxant response of the surrounding ASM, which does not expresses NPR-A. This review explores the teleological activities and paradoxical effects of BNP with regard to chronic obstructive respiratory disorders, and provides an excursus on the main scientific findings that explain why BNP should be considered much more than a biomarker

The 95zr(n, gamma)96zr cross section from the surrogate ratio method and its effect on the s-process nucleosynthesis

The 95Zr(n,gamma)96Zr reaction cross section is crucial in the modelling of s-process nucleosynthesis in asymptotic giant branch stars because it controls the operation of the branching point at the unstable 95Zr and the subsequent production of 96Zr. We have carried out the measurement of the 94Zr(18O,16O) and 90Zr(18O,16O) reactions and obtained the gamma-decay probability ratio of 96Zr* and 92Zr* to determine the 95Zr(n,gamma)96Zr reaction cross sections with the surrogate ratio method. Our deduced maxwellian-averaged cross section of 66+-16 mb at 30 keV is close to the value recommended by Bao et al. (2000), but 30% and more than a factor of two larger than the values proposed by Toukan & Kappeler (1990) and Lugaro et al. (2014), respectively, and routinely used in s-process models. We tested the new rate in stellar models with masses between 2 and 6 Msun and metallicities 0.014 and 0.03. The largest changes - up 80% variations in 96Zr - are seen in models of mass 3-4 Msun, where the 22Ne neutron source is mildly activated. The new rate can still provide a match to data from meteoritic stardust silicon carbide grains, provided the maximum mass of the parent stars is below 4 Msun, for a metallicity of 0.03.Comment: 10 pages, 6 figures, accepted for publication in Ap